1. Field of the Invention
The present invention is related to food industry, and, in particular, to instant freeze-dried coffee production technology used in coffee production industry.
2. Description of the Related Art
An instant coffee, as a final product, should comply with the key requirements which are often contradictory: to obtain the desired taste, aroma and the body of freshly brewed coffee dissolved in a cup, while preserving organic and inorganic substances contained in a regular coffee. It is also important to maintain coffee components beneficial for human nutrition (e.g., tannins, carbohydrates, alkaloids, various mineral substances—some several hundreds of organic compounds), which ultimately constitute the unique coffee aroma. However, these requirements are often subjective and contradictory.
Conventional instant freeze-dried coffee typically preserves well the beneficial qualities of components contained in the regular coffee beans. However, in order to improve the taste and the aroma, there is a need to draw the volatile aroma fractions out of coffee substrate at the certain production stage, and then recover them in the processing at another (later) production stage. Also, other methods to make the taste and aroma of instant coffee close to the regular coffee are used. These methods are described in detail in the following publications:
Application RU 2003122213, published on Feb. 20, 2005, Craft Foods Holdings, Inc. (US) “Composition of coffee aroma, aromatic composition for preparing coffee drink and composition of instant coffee”;
Application RU 2002107325(A), published on Feb. 20, 2005, Société de Produits Nestlé S. A., “Method for extracting coffee aromatic components and aromatized powder soluble coffee containing coffee aromatic components”; and
Application KR 20040082227 A, published on Sep. 24, 2004. “Production of instant coffee product containing aroma extract while having palatability and flavor similar to green coffee beans”
A conventional method for instant freeze-dried coffee production includes raw material preparation (cleaning and scaling of green coffee beans), mixing of coffee beans based on a certain recipe (mix of various green coffee types in a necessary ratio), roasting, cooling, grinding followed by the extraction of resulting mixture, mixture concentrating, filtration and sublimation (freezing, breaking up the frozen extract particles, freeze-drying), pre-packaging and packaging. This method is described in detail in the following publications:
Application FR 2003131184, published on Jan. 20, 2005, Société de Produits NestléS. A., Coffee aroma-containing component and method of its preparation;
F. G. Nakhmedov., Coffee products technology. M: Light and food industry, 1984, p. 79.
It is possible to use the above technological production cycle partially, when a special substrate used for sublimation—a concentrated liquid extract is taken in a ready-to-use form. For example, this extract can be obtained from other manufacturers or received from a long-term storage warehouse.
The main disadvantage of the standard method is the fact that the obtained highly soluble freeze-dried granules do not possess the taste and the aroma characteristics of a fresh regular coffee, because during the course of full coffee processing, a considerable loss of the aroma, as well as of coffee taste-generating substances, occurs.
The purpose of obtaining freeze-dried coffee with organic characteristics of regular roasted coffee cannot be solved by simply mixing ingredients in a cup or during the process of the final product packaging. The packaged coffee product has to be homogeneous, and the dissolved coffee should have an attractive and appetizing look.
Accordingly, there is a need for a method for preserving the organic qualities of regular freshly brewed coffee in the production process of instant freeze-dried coffee.